Hydraulic pump



1947. B.- E. FOLKE EI'AL 2,430,394

ntnmuuc ruur Filed on. 25, 1945 5 Sheets-Sheet 1 F/ V -9 I 68 EHL-PHMSHEMBD 4 mmmns.

ATTORNEY.

newer 1:. rout Nov. 4, 1947. B. E. FOLKE ETAL 2i,,43,394-

' HYDRAULIC PUMP Filed Oct. 25, 1945 r? ii ixeeis-fiima a 66 I 5/ 5 5 e: 7059 G4 67 BY WZQU/MM ATTORNE X Nov. 4, 1947.

B. E. FOLKE arm. 2,430,394

* HYDRAULIC PUIP Filed Oct. 25, 1945 v 5 Sheets-Sheet 3 E D em L 0 0 P T r E 5 W 0 WM... 03 m 22 2 NM 9 oh/ 9 I I n NOV. 4, 1947. FQLKE r 2,430,394

I mmune PUMP I Filed Oct. 25, 1945 5 Shee ts-Sheet 4 30167 5. F01. x5 enuw n. 5110020 INVEN TORS.

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ATTORNEY.

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Nov. 4, 1947.

Fla/3 9* D43 l n B. E. FOLKE ETAL" .mmmmmc run? Filed Oct. 25, 1945 5 Sheets-Sheet 5 BENGT-f. rouaz enLP/m. sue-P020 INVENTORS.

. BY mil/m ATTO RNEY.

Patented Nov. 4, 1947 HYDRAULIC PUMP Bengt E. Folke. Mamaroneck, and Ralph H. Shep'- ard, New York, N. ,Y., assignors to Nathan Manufacturing Company, New York, N. 'Y., corporation of New York Application October 25, 194 5, Serial No. 624,552

This invention relates to hydraulic pumps of the type described in Patent No. 2,369,345, covering an invention made by one of the present joint inventors, and has for its object certain improvements in such Dumps.

The pump illustrated in the patent comprises able memberso that a single adjustment suffices for all. We have also provided means, controlled by the discharge pressure of the pump, for automatically adjusting the lateral displacement of the fixed pivot or pivots to vary the piston stroke and thereby maintain a constant discharge pressure.

In the drawings, which illustrate a preferred embodiment of the invention,

' Fig. 1 is a plan view of th pump assembly;

16 Claims. (01. 103- 151) Fig. 2 is a left hand side view of the same show- Fig. 4 is a fragmentary sectional view along the plane of line 4-4 in Fig.2;

Fig. 5 is a sectional view through the left hand side portion of the pump containing the control valve along the plane of line 55 in Fig. 2;

Fig. 6 is a fragmentary sectional view through the right hand side-portion of the.pump showinga relief valve;

Fig. 7 is a cross sectional view, its left half along the plane of line la-la in Fig. 3, and its right half along the plane of line lb- 1b in Fig. 3;

Fig. 8 is a cross sectional view, its left half along the plane of line 8a-8a in Fig. '3, and its right half along the plane of line 8b-8b, in Fig. 3, some of the parts havingbeen omitted for the sake of clearness;

Fig. 9 is a cross sectional 'view along the plane of line 9-9 in Fig. 3;

Fig. 10 is a cross sectional view along the plane of line I0lli in Fig. 3;

11 is a cross sectional view, partly, diagrammatic, of a combinationof Figs; 2 and 10 to indi- 2 cate the flow of fluid between the control valve and piston stroke regulating mechanism;

Fig. 12 is a diagrammatic view showing the action of the regulating mechanism with the pistons at their minimum or no strokes; and

Fig. 13 is a similar diagram showing the pistons at their maximum strokes.

Like characters of reference denote similar parts throughout the several drawings and the following specification. V

The pump illustrated is housed within a casing 9 comprising a cylinder block ill, a manifold II, a body l2 and a base |'3. The manifold II is provided with an inlet l4 supplying liquid through inlet passages l5, 16, ll, Ila and I8 to annularly disposed cylinder l9 each fitted with a piston 20. Each piston 20 has an elongated transverse duct 2| connected with a 1ongitudinal duct 2la in communication with the end of its cylinderand each'is rotated and reciprocated in its cylinder in the manner described in U. S. Patent No. 2,369,345, and also as described later in this specification, causing duct 2| to communc'ate alternately with inlet passage l8 and discharge passage 22 which, through passages 23, 24 and 25, communicates with an outlet 26 in the manifold.

A suitable drive connection, 21 rotates a crank shaft 28 supported in a bearing sleeve 29. The crank shaft 28 is provided with a crank pin 30 on which a disk 3| is mounted. A counter balance weight 32 is secured by means of a key 33 to an extension 34 of the crank pin 30. The crank shaft 28 is held in longitudinal alinement by means of a shoulder 35 on crank pin 3!] and a thrust face 36.

The crank shaft 28 is provided at its outer end with an oil seal 13 to prevent leakage of fluid around the end of the shaft. A passage 14 connects with an outlet 15 which may be used to relieve exces pressure from the interior of the -located with respect to the pistons '20, and the eccentricity with respect .to the pistons 20 is the same as the eccentricity of the crank pin 30 with respect to the crank shaft 28. ,Rotation of the crank shaft 28 therefore results in corresponding rotation of the pistons 20.

The outer end of crank pin 38 of each piston 20 is provided with a socket which receives one ball 39 of a ball link 40 and serves as a pivot therefor. The ball 39 is movably secured in the socket by means of a retainer 4|. The retainer 4| is locked in place by suitable means (not shown) The ball link 49 is provided at its other end with a ball 43 likewise secured in a socket 44 of a regulating disk 45 by means of a retainer ring 46, the socket 44 serving as a fixed pivot for the link 40. The regulating disk 45 is rotatably supported on the bearing sleeve 29 and is provided with a pin 49 which, as shown in Figs. 10 and 11, fits in a slot 59 of a regulating cam which is fulcrumed around a fulcrum post 52. The regulating cam 5| is turned about its fulcrum 52 by means of two hydraulic plungers 53 and 54 fitted in their respective cylindrical chambers 55 and 56, the ends of which are closed by caps 51 and 58. .Thus as the hydraulic plungers 53 and 54 turn the regulating cam 5| about its fulcrum 52, the regulating disk 45 is likewise turned through the same limited angle with respect to the sleeve 29.

Referring now to Fig. 12, it will be noted that when the regulating disk 45 is turned into a position where the ball terminal 43 of the link 49 is in line with the center of piston 20, the rotation 'of the piston 29 as imparted to it by the disk 3|, does not result in any reciprocating movement of the piston. On the other hand, referring to Fig. 13, it will be noted that when the disk 45 has been rotated a certain angle so that ball terminal 43 of the link 40 which serves as a universal coupling has been displaced a distance A from the center line of the piston 20, the piston will be reciprocated while it is being rotated, The amplitude of the reciprocation B is a function of the distance A. By turning the regulating disk 45, it will be seen therefore that the distance A may be varied to any desired amount and the stroke B of the pistons may also be regulated to any desired amount between zero and maximum.

As previously explained, the regulating disk 45 is actuated by means of the hydraulic plungers 53 and 54. These plungers receive their driving impulses from a cylindrical control valve 59 shown in Figs. 2, 5 and 11. The control valve is subjected to pump discharge pressure communicated from outlet 26 through passage 60 to one end 6| of the valve 59. The other end of the valve 59 is subjected to pressure from a regulating spring 62,

which may be set to maintain any desired discharge pressure.

When the pump is stopped, regulating spring 62 moves control valve 59 toward one end of its travel, and a spring 63 inside plunger 53 urges the plunger toward the maximum capacity position shown in the lower part of Fig. 11. Thus, the pump is ready for operating the regulating mechanism whenever the pump is started. Upon starting the pump the discharge pressure acts on the end surface 6| of the control valve 59 as stated before. When this pressure becomes suflicient to overcome the resistance of spring 62, the' valve 59 moves'and its central piston portion 64 uncovers a supply port 65, admitting fluid under pressure from the pump discharge outlet 26 through port 65 and passage 66 to cylinder 56. An end piston portion 61 of valve 59 likewise uncovers a release port 68, releasing fluid through passage 69 from cylinder 55. The upper part of Fig. 11 shows the control valve with the ports uncovered as just described.

Plunger 54 in cylinder 56 is subjected to fluid pressure and therefore moves and swings cam 5| toward a reduced capacity position as shown in Fig. 10. Reducing the pumping capacity suflfl-' ciently results in reducing the discharge Pressure acting on the control valve thus reversing the action. Or, in other words, when the fluid pressure on the end surface 6| of control valve 59 becomes less than the pressure of spring 62, the valve moves back, the central piston portion 64 closing communication between supply port 65 and passage 66 connected with cylinder 56, and the end piston portion 61 closes connection between cylinder through passage 69 and release port 68.

A further drop in pump discharge pressure results in spring 62 moving the valve further in the direction last mentioned, so that its central piston portion 64 opens communication between supply port and passage 69 leading to cylinder 55, and so that a piston portion 10 (at the end opposite 61, previously mentioned) uncovers a release port 1|, releasing fluid from cylinder 56 through passage 66. This will cause piston 53 to swing cam 5|, displace piston 54 and, through pin 49, partly rotate the regulating disk 45 to an increased capacity position.

Thus equilibrium is attained to maintain the discharge pressure within practical limits while the required volume may vary. Diagrammatic Fig. 11 clearly illustrates the relation between the control mechanism and the operating means for the regulating disk.

Fluid used to operate the regulating mechanism can be discharged through release ports 68 and 1| together with leakage past plungers 53 and 54 and past pistonsv 20, into the body portion I2 of the pump. If the fluid is a satisfactory lubricant, it can be conducted through a suitable groove 12 along bearing 13 to passage I4 in order to lubricate shaft 28. Should the passage through groove 12 prove inadequate to carry oil all of the fluid, a check valve 16 shown in Fig. 6 operates to prevent excessive pressure building up within the body l2. The valve 16 passes fluid from passage TI, which is in communication with the interior of body l2, to passage 18 which leads into passage I4 and the outlet 15. To insure normal resistance to this by-passing of lubricant around groove 12, a light spring 19 holds valve 16 on its seat.

It will be noted that while the arrangement described is entirely automatic in its action, the control may instead be manual or modified in a manner to suit individual installation requirements.

Moreover, while the drawings show a plurality of piston units in the pump, the invention is not to be limited to more than one; only one piston unit may be found to be entirely satisfactory.

Further, while the drawings show a 'cam 5| operably connected to the disk 45, and the plungers 53 and 54 adapted to press against opposite sides of the cam to turn the disk in either direction, it is obvious that the cam can be omitted and the plungers contact lugs on the disk'to turn it. I

Many other changes in the form, proportion, combination of parts and minor details of con-- struction may be resorted to without departing from the principles or sacrificing any of the advantages of the invention. as defined in the appended 'claims.

What we claim as new, is:

1. A pump comprising a cylinder having inlet and discharge passages, a rotary and reciprocatory piston in the cylinder having means for alternately placing the inlet and discharge passages in communication with the, cylinder as the piston rotates, an eccentric pivot carried by the pistween the pivots, means for rotating and thereby f reciprocating the piston, and means controlled by the discharge pressure of the pump for adjusting the lateral displacement of the fixed pivot to regu-- late the stroke of the piston.

2. A pump comprising a cylinder having inlet and discharge passages; a rotary and reciprocatory piston in the cylinder having means for al-,

ternately placing the inlet and discharge passages in communication with the cylinder as the piston rotates, an eccentric pivot carried by the piston, a fixed pivot laterally displaced with reference to the piston axis, a universal coupling between the pivots, means for rotating and thereby reciprocating the piston, and means controlled by the discharge pressure of the pump for automatically adjusting the lateral displacement of the fixed pivot to regulate the stroke of the piston and maintain a constant discharge pressure.

3. A pump comprising a casing having an inlet and an outlet, a plurality of cylinders, each cylinder having an inlet passage in communication with the inlet and a discharge passage in communication with the outlet, a rotary and reciprocatory piston in each cylinder having means for alternately placing. said inlet passage and said discharge passage in communication with the cylinder as the piston rotates, an eccentric pivot carried by each piston, a fixed'pivot for each piston laterally displaced with reference to the piston axis, a universalcoupling between each fixed and eccentric pivot, means for rotating and thereby reciprocating the pistons, and movable means interconnecting all of the fixed pivots for simultaneously adjusting their lateral displacement to regulate the stroke of the pistons.

a 4. A pump comprising a casing having an inlet and an outlet, a. plurality of cylinders, each cylinregulate the stroke. of the piston andmaintain a constant discharge pressure. 6- A P p prising a casing having an inlet and an outlet, a plurality of annularly disposed cylinders, each cylinder having an inlet. passage in communication with the inlet and a discharge passage in communication with the outlet, a ro-' tary and reciprocatory piston in each cylinder having means for alternately placing the inlet and discharge passages in communication with the cylinder as the piston rotates, an eccentric pivot carried by each piston, a rotary disk, a, plurality of annularly disposed fixed pivots on the disk corresponding in number to the cylinders. a universal coupling between each eccentric pivot and a fixed pivot, means for rotating and thereby,reciprocating the pistons, and means for turning the disk to adjust the lateral displacement of the fixed pivots with reference to their corresponding piston der having an inlet passage in communication reciprocating the pistons, and means controlled by the discharge pressure of the pump for simultaneously adjusting the lateral displacement of all the fixed pivots to regulate the stroke of the pistons.

5. A pump comprising a casing having an inletand an outlet, a plurality of cylinders, each cylin der having an inlet passage; in-communication with the inlet and a discharge passage in communication with the outlet, a rotary and reciprocatory piston in each cylinder having means for alternately placing said inlet passage and said discharge passage in communication with the cylinder as the piston rotates, an eccentric pivot carried by each piston, a fixed pivot for each piston laterally displaced with reference to the pisaxes and thus regulate the stroke of the piston. 7. A pump comprising a casing having an inlet and an outlet, a plurality of annularly disposed cylinders, each cylinder having an inlet passa e in communication with the inlet and a discharge passage in communication with the outlet, a rotary and recoprocatory piston in each cylinder having means for alternately placing the inlet and discharge passages in communication with the cylinder as the piston rotates, an eccentric pivot carried by each piston, a rotary disk, a plurality of annularly disposed fixed pivots 0n the disk corresponding in number to the cylinders, a universal coupling between each eccentric pivot and a fixed pivot, means for rotating and thereby reciprocating the pistons, and means controlled by-the discharge pressure of the pump for automatically turning the disk to adjust the lateral displacement of the fixed pivots with reference to their corresponding piston axes and thus regulate the stroke of the piston and maintain a, constant discharge pressure;

8. A pump comprising a casing having an inlet and an outlet, a plurality of annularly disposed cylinders, each cylinder having an inlet passage in communication with the inlet and a discharge passage in communication with the outlet, a rotary and reciprocatory piston in each cylinder having means for alternately placing the inlet and discharge passages in communication with the cylinder as the piston rotates, an eccentric pivot carried by each piston, a rotary disk, a pinrality of annularly disposed fixed pivots on the disk corresponding in number to the cylinders, a universal coupling between each eccentric pivot and a fixed pivot, means for rotating and thereby reciprocating the pistons, and means for turnme the disk to adjust the lateral displacement oi the fixed pivots with reference to their correton axis, a universal coupling between each fixed spending piston axes and thus regulate the stroke oi the piston, the means for turning the disk including a rotatably supported cam interlocked with the disk, means to turn the cam in one direction to effect a greater stroke of the piston,

and means to turn the cam in an opposite direction to effect a lesserstroke or the piston.

9. A pump comprising a casing having an inlet and an outlet, a plurality of annularly disposed cylinders, each cylinder having an inlet passage in oommunication with the inlet and a discharge passage in communication with the outlet, at rotary and reciprocatory piston in each cylinder having means for alternately placing the inlet and discharge passages incommunication with the cylinder as the piston rotates, an eccentric pivotv carried by each piston, a rotary disk, a pluamazes I rality of annularly disposed fixed pivots on the disk corresponding in number to the cylinders, a universal coupling between each eccentric pivot and a fixed pivot, means for rotating and thereby reciprocating the pistons, and means controlled by the discharge pressure of the pump for automatically turning the disk to adJust the lateral displacement of the fixed pivots with reference to their corresponding piston axes and thus regulate the stroke of the piston and maintain a constant discharge pressure, the last named mean including a plunger within a chamber in communication with the discharge pressure adapted to turn the disk in one direction to eflect a. greater stroke or the piston when the discharge pressure drops below a predetermined point, and another plunger within a chamber in communication with the discharge pressure adapted to turn the disk in an opposite direction to effect a lesser stroke of the piston when the discharge pressure increases above the predetermined point.

10. A pump comprising a, casing having an inlet and an outlet, a plurality of annularly disposed cylinders, each cylinder having an inlet passage in communication with the inlet and a discharge passage in communication with the outlet, a rotary and reciprocatory piston in each cylinder having means for alternately placing the inlet and discharge passages in communication with the cylinder as the piston rotates, an eccentric pivot carried by each piston, a rotary disk, a plurality of annularly disposed fixed pivotson the disk corresponding in number to the cylinders,

a universal coupling between each eccentric pivot means including a rotatably supported cam interlocked with the disk, a plunger within a chamber in communication with the discharge *pressure adapted to turn the cam and disk in one direction to effect a greater stroke of the piston when the discharge pressure drops below a predetermined point, and another plunger within a chamber in communication with the discharge pressure adapted toturn the cam and d sk in an opposite direction to effect a lesser stroke of the piston when the discharge pressure increases above the predetermined point. 1

11. A pump comprising a casing having an inlet and an outlet, a plurality of annularly disposed cylinders, each cylinder having an-inlet passage in communication with the inlet and a discharge passage in communication with the outlet, a rotary and reciprocatory piston in each cylinder having means for alternately placing the inlet and discharge passages in communication with the cylinder as the piston rotates, an eccentric pivot carried by each piston, a rotary disk, a plurality of annularly disposed fixed pivots on the disk corresponding in number to the cylinmeans including a rotatably supported cam interlocked with the disk, a plunger within a chamher in communication with the discharge pressure adapted to turn the cam and disk in one direction to' effect a greater stroke of the piston when the discharge pressure drops below a predetermined point, another plunger within a chamber in communication with the discharge pressure adapted to turn the cam and disk in an opposite direction to eilect a lesser stroke 01 the piston when the discharge pressure increases above the predetermined point, and a valve responsive to fluctuations in discharge pressure controlling communication between the outlet and either of the chambers.

12. A pump comprising a casing having an inlet and an outlet, a plurality of cylinders, each cylinder having an inlet passage in communication with the inlet and a discharge passage in communication with -the outlet, a rotary and reciprocatory piston in each cylinder having means for alternately placing said inlet passage and said discharge passage in communication with the cylinder as thelpiston rotates, an eccentric 'pivot carried by each piston, a rotatably supported disk, a fixed pivot for each piston on the disk laterally displaced with reference to the piston axis, a universal coupling between each fixed and eccentric pivot, means for rotating and thereby reciprocating the pistons, and means for simultaneously and automatically adjusting the lateral displacement .of all the fixed pivots on the disk to regulate the stroke of each piston and maintain a constant discharge pressure at the outlet including a plunger within a chamber in communication with the discharge pressure adapted to turn the disk in one direction to eflect a greater stroke of the piston when the discharge pressure drops below a predetermined point, another plunger within a chamber in communication with the discharge pressure adapted to turn the disk in an opposite direction to eii'ect a lesser stroke of the piston when the discharge pressure increases above the predetermined point, and a valve responsive to fluctuations in discharge pressure controlling communication between the outlet and either of the chambers.

ders, a universal coupling between eacheccen- 13. In a pump, a cylinder having inlet and dis-- the link with respect to the piston axis is varied to regulate the stroke of the piston.

14. In a pump, a cylinder having inlet and discharge passages, a rotary and reciprocatory piston in the cylinder having means for alternately placing the inlet and discharge passages in communicatlon with the cylinder as the piston rotates. a rotary disk, a link having one end eccentrically connected to the piston and its other end to the disk laterally displaced with reference to the piston axis, driving mechanism, concentric with said disk, for rotating and thereby reciprocating the piston, and means to partly rotate the disk whereby the angle of the link with respect to the piston axis is varied to regulate the stroke of the piston.

15. In a pump, a cylinder having inlet and discharge passages, a rotary and reclprocatory piston in the cylinder having means for alternately placing the inlet and discharge passages in communication with the cylinder as the piston rotates, a rotary disk, a link having one end eccentrically connected to the piston and its other end to the disk laterally displaced with reference to the piston axis, driving mechanism for rotating and thereby reciprocating the piston, and means controlled by the discharge pressure of the pump to partly rotate the disk whereby the angle of the link with respect to the piston axis is varied to regulate the stroke of the piston.

16. In a pump, a cylinder having inlet and discharge passages, a rotary and reciprocatory piston in the cylinder having means for alternately placing the inlet and discharge passages in com- 1 munication with the cylinder as the piston r0- tates, a rotary disk, a link having one end 'eccentrically connected to the piston and its other end to the disk laterally displaced with reference to .the piston axis, driving mechanism for rotating REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,006,378 Hajek Oct. 17, 1911 2,369,345 Folke Feb. 13, 1945 

